[Math] Improve Math.Min/Max and BoundingSphere.CreateFromAABB performance;

[Rendering] Camera uses AABB by default since no meaningful perf improvement was found and it's less accurate;
[Rendering] Optimize Renderable iteration performance when clearing culling states;

Author: LittleCodingFox

Engine/Staple.Core/Math/BoundingSphere.cs

@@ -48,7 +48,7 @@ public static BoundingSphere CreateFromAABB(AABB aabb)
         temp = aabb.max - center;
         distanceSquare = Vector3.Dot(temp, temp);
 
-        maxDistanceSquare = Math.Max(maxDistanceSquare, distanceSquare);
+        maxDistanceSquare = distanceSquare > maxDistanceSquare ? distanceSquare : maxDistanceSquare;
 
         return new(center, Math.Sqrt(maxDistanceSquare));
     }

Engine/Staple.Core/Math/Math.cs

@@ -133,22 +133,23 @@ public static class Math
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static float Max(params float[] f)
     {
-        float t;
-
-        if(f.Length > 0)
-        {
-            t = f[0];
-        }
-        else
+        if(f.Length == 0)
         {
             return 0;
         }
 
+        float t = f[0];
+
         var length = f.Length;
 
         for(var i = 1; i < length; i++)
         {
-            t = System.Math.Max(t, f[i]);
+            var value = f[i];
+
+            if (value > t)
+            {
+                t = value;
+            }
         }
 
         return t;
@@ -157,22 +158,23 @@ public static float Max(params float[] f)
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static float Min(params float[] f)
     {
-        float t;
-
-        if (f.Length > 0)
-        {
-            t = f[0];
-        }
-        else
+        if (f.Length == 0)
         {
             return 0;
         }
 
+        float t = f[0];
+
         var length = f.Length;
 
         for (var i = 1; i < length; i++)
         {
-            t = System.Math.Min(t, f[i]);
+            var value = f[i];
+
+            if (value < t)
+            {
+                t = value;
+            }
         }
 
         return t;

Engine/Staple.Core/Rendering/Camera/Camera.cs

@@ -164,11 +164,7 @@ public Vector3[] Corners(Transform cameraTransform)
     /// <returns>Whether it's visible</returns>
     public bool IsVisible(AABB bounds)
     {
-#if FRUSTUM_TEST_AABB
         return frustumCuller.AABBTest(bounds) != FrustumResult.Invisible;
-#else
-        return frustumCuller.SphereTest(BoundingSphere.CreateFromAABB(bounds)) != FrustumResult.Invisible;
-#endif
     }
 
     /// <summary>

Engine/Staple.Core/Rendering/RenderSystem/RenderSystem+Internal.cs

@@ -81,7 +81,12 @@ internal class DrawBucket
     /// <summary>
     /// All renderables
     /// </summary>
-    private readonly List<Renderable> renderables = [];
+    private Renderable[] renderables = new Renderable[1024];
+
+    /// <summary>
+    /// Amount of renderables used
+    /// </summary>
+    private int renderableCount;
 
     /// <summary>
     /// The renderer backend
@@ -251,7 +256,7 @@ public void Update()
     /// </summary>
     internal void ClearCullingStates()
     {
-        for (var i = 0; i < renderables.Count; i++)
+        for (var i = 0; i < renderableCount; i++)
         {
             renderables[i].cullingState = CullingState.None;
         }
@@ -282,7 +287,8 @@ public void WorldChanged()
         lock (lockObject)
         {
             renderQueue.Clear();
-            renderables.Clear();
+
+            renderableCount = 0;
 
             foreach (var systemInfo in renderSystems)
             {
@@ -295,7 +301,14 @@ public void WorldChanged()
                 {
                     if (entityInfo.Item1.TryGetComponent(systemInfo.system.RelatedComponent, out var component))
                     {
-                        renderables.Add((Renderable)component);
+                        renderableCount++;
+
+                        if(renderableCount > renderables.Length)
+                        {
+                            Array.Resize(ref renderables, renderables.Length * 2);
+                        }
+
+                        renderables[renderableCount - 1] = (Renderable)component;
                     }
                 }
             }